CEL P0171 - Catalytic Converter
- Thread starter mvp
- Start date
So the CEL light came on and the dealer said I need a new catalytic converter at $900. What are my options? I will definitely get it done at an independent shop, but that still may cost over $500. Looking for opinions on what to doopcorn:
You have 2013 w 1.4 litre?
2013 CHEVROLET SONIC 1.4L L4 Turbocharged Catalytic Converter | RockAuto
Yes, I have 1.4T. Is this a bolt on situation that I can tackle myself?
Blue Moon Sonic
New member
Common causes include:
- Intake or vacuum leaks
- Clogged or faulty Mass Air Flow sensor (MAF)
- Faulty PCV valve
- Stuck open purge valve/solenoid
- Faulty oxygen sensor
- Improperly installed aftermarket cold intake
- Low fuel pressure
- Clogged catalytic converter <--- Not the cause
Last time I checked, a P0171 indicates the car is running too lean. Usually this happens if there is a leak somewhere on the intake side. If you had a bad cat or something wrong with the exhaust, you'd be throwing other codes with the lean code. So let's say you have a bad cat and have a P0171. You would also be showing a P0420, P0430, or something else related to the catalytic converter or other exhaust related codes.
I would make sure your not getting a vacuum or boost leak from anywhere in the car. If there is non audible and visible and since you have a 1.4. Pull off the PCV hose from the top of the intake manifold and check to see if your orange check valve is still there. If It's missing, It'll act as though you have a vacuum/boost leak and will cause a lot more headaches down the road if not checked and fixed.
- Intake or vacuum leaks
- Clogged or faulty Mass Air Flow sensor (MAF)
- Faulty PCV valve
- Stuck open purge valve/solenoid
- Faulty oxygen sensor
- Improperly installed aftermarket cold intake
- Low fuel pressure
- Clogged catalytic converter <--- Not the cause
Last time I checked, a P0171 indicates the car is running too lean. Usually this happens if there is a leak somewhere on the intake side. If you had a bad cat or something wrong with the exhaust, you'd be throwing other codes with the lean code. So let's say you have a bad cat and have a P0171. You would also be showing a P0420, P0430, or something else related to the catalytic converter or other exhaust related codes.
I would make sure your not getting a vacuum or boost leak from anywhere in the car. If there is non audible and visible and since you have a 1.4. Pull off the PCV hose from the top of the intake manifold and check to see if your orange check valve is still there. If It's missing, It'll act as though you have a vacuum/boost leak and will cause a lot more headaches down the road if not checked and fixed.
Blue Moon Sonic
New member
I barely listen to what the dealership says unless I'm able to have an intelligent conversation with the service department. Most dealerships just want your money. This is why I advocate working on your own vehicle if you have time, space and tools. Though generally best to learn on a winter beater after the snow season.
dbratboy92
New member
As a dealer tech I can say your accurate about most dealerships. As far as the code that is a lean code. p0420 is almost definitely a bad cat unless there is a very small exhaust leak after the cat before the downstream O2 sensor. Because P0420 isn't reading your fuel trim it is compacting your bank 1 to bank 2 O2 sensor data. So the only thing that can affect that is an exhaust leak between the two.
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